In a variety of applications, a drive actuator can be used to position or orient such items as a propulsion system, a camera, a satellite, or a telescope. From time to time, the object being positioned by the drive actuator may need to undergo maintenance. In such situations, maintenance is made easier for the technician by locking the drive actuator to prevent movement of the object.
In some conventional applications, a powered brake is provided to lock the drive actuator. As the name implies, the powered brake requires a power source, such as a battery for DC powered brakes. Generally, the power source is a separate power source from the primary power source used to drive the drive actuator. Accordingly, to lock the drive actuator during maintenance, the system has to be designed with a separate power source, which increases the cost of the system. Further, in some instances, the separate power source can be unreliable, such as a battery that is nearing its fully discharged state.
A further disadvantage of powered brakes is that they have to be disengaged when maintenance is complete. Otherwise, the drive actuator will not function properly, if at all. Attempts to address that problem often require special tooling, create potential sources of foreign object damage and misuse, or require increased motor power to compensate for the drag created by the powered brake.
Embodiments of the presently disclosed invention provide a locking mechanism that overcomes the disadvantages described above. In particular, embodiments of the locking mechanism described hereinbelow are self-releasing and do not require a separate power source. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.